Who is Muriel's Mother from Nine Stories and what is their importance?

Muriel's mother is the voice of worry in the story. It is through her conversation with Muriel that Seymour's odd behavior is first described. She lives in New York with Muriel's father and has come to disapprove of Muriel's marriage to Seymour. She encourages her daughter to leave her husband, and even offers to come and get her.